A great deep dive into how the linux kernel handles and allocates memory. Found the breakdown of a number things extremely useful. For example:
- How processes are allocated virtual memory
- How swap works
- Buffers, Cache
- Overflow
- Forking and the copy on write implementation in the kernel.
A real eye-opener on just how efficient memory management is at the lower levels. Joshua delivered this one very well, and kept the audience engaged throughout.

Thanks for the great feedback. I'm absolutely amazed (in a good way) that so many people find this topic interesting.

Anonymous: "This should've covered how PHP deals with memory allocation, it wasn't a Linux conference."
I absolutely understand why you think this, but i must respectfully disagree. Granted: this was an advanced & in-depth talk about a subject that is out of everybody's (and partially including my) comfort-zone. This however is a "good thing"(tm). One of the major shifts at PHP conferences I have seen since a few years, is that PHP developers are broaden their horizon in every direction possible, because quite frankly: we aren't PHP developers, we are developers who happen to use PHP a lot.

Even if these kind of talks do not have directly a practical use on your next working day (although, I think it actually might), they are also there to give you more insight in the things we take for granted each and every day (take a look at https://github.com/alex/what-happens-when, which shows you what's going on when you type google in a browser. You'll be amazed). Having more knowledge - inside or outside your comfort zone), will help you make better calls on problems you are facing every day, and will help you grow in area's you aren't even expecting or focussing on.

@Miguel I actually have prepared those slides! I've not added them to the final presentation, because it took almost 20 minutes to explain the concepts of memory, zvals, memory allocs in the php core and it would help to answer the question "how much memory (and how) is my system using". But i'm happy to talk about that in another talk :-)

Granted it doesn't mention PHP, but as a developer you shouldn't need somebody else to tell to you your scripts are using too much memory.... Now you know how to find out yourself before you deploy memory monsters to production!!

Brilliant - well presented and thought out. My only why not 5 stars, perhaps was expecting a little bit more insight into PHP itself and how to solve memory issues, or maybe a bit of relevance into the how/if the tools work with cloud deployments.

Looking at the programme it was the most relevant of all the sessions on at that time. However, I felt that the content was more focussed on Linux architecture than PHP itself. Learnt the odd thing but as a developer and not a systems person didn't get as much out of it as I thought I might.

Joshua delivered the talk well and im sure those more at a systems level would have gained more from it.